This disclosure relates generally to imaging systems, methods and apparatus, and more particularly to volume holographic imaging systems, methods and apparatus that obtain enhanced images from multiple depths within an object.
Microscopic imaging systems are beneficial for, among other things, biomedical and clinical applications. Volume holographic microscopy (VHM) has been developed as a microscopic instrument for spatial-spectral imaging of objects. Volume imaging systems have many useful applications, such as spectral and three spatial dimensional biological imaging (known as four-dimensional (4D) imaging), endoscope imaging systems, spectrometers, and the like.
In VHM, holographic gratings are superimposed in a volume recording material such that each grating obtains depth-resolved information from different depths within the object. Microscopic imaging systems incorporating VHM visualize features of the object at different focal planes. Each focal plane is projected to a different lateral location on a camera. Thus, the entire object volume is imaged slice-wise onto the camera without the need for electrical or mechanical scanning. However, many objects of interest are composed of weak phase features with poor contrast and are barely observable with VHM.